Frac responsibly and risks – and quakes – are small
Mike Stephenson, NewScientist
THE US has led the world in extracting gas from shale but interest is now spreading elsewhere. The British Geological Survey (BGS) recently estimated that the UK has 150 billion cubic meters of shale gas, about half of its more conventional reserves. World shale gas reserves are 450,000 billion cubic meters.
Shale gas has been a success story in the US. But fracing has had some bad press, with the main concerns being earthquakes and the contamination of groundwater with gas and chemicals. In the documentary film Gasland, for example, a man is shown igniting water from his kitchen tap.
Some of the worries are justified. Badly managed fracing has recently been shown to have contaminated water wells in Wyoming, though this involved a shallow sandstone reservoir rather than much deeper shale. But with so many vested interests, getting reliable information is difficult. So peer-reviewed science must play a big role in deciding what the risks are.
Most geologists see contamination of aquifers as unlikely because of the great difference between the depths at which fracing is carried out and the shallow aquifers from which we get our water. more
01/27/2012